


Universal Constant

by Daiako (Achrya)



Category: Haikyuu!!
Genre: Alpha/Beta/Omega Dynamics, Alternate Universe - Regency, Biting, Claiming, Explicit Sexual Content, Forbidden Love, Knotting, M/M
Language: English
Status: Completed
Published: 2018-04-23
Updated: 2018-05-26
Packaged: 2019-04-26 19:01:32
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 4,440
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14408517
Author URL: https://archiveofourown.org/users/Achrya/pseuds/Daiako
Summary: A collection of Asanoya omegaverse ficlets written for tumblr requests.1. A!Asahi/O!Noya, Hands/Stop moving so I can claim you2. A!Asahi/O!Noya, How Does that Feel3. O!Asahi?A!Noya, Kneel, Victorian/Regency





	1. Chapter 1

**Author's Note:**

> Written for tumblr requests, Hands and Stop Moving so I can Claim You. Anon wanted a more dominate/alpha Asahi and...well. I tried to achieve that. I...don't know how it went.

Yuu had never put much thought in claiming before meeting Asahi. He’s an omega, so it’s a thing his parents talked to him about because it’s a part of an omega’s life, but Yuu has never cared. The whole thing seemed sort of dumb and one sided to him, alphas going around leaving their marks on omegas or betas but never being marked back, biting in scars and bruises that screamed ‘this one belongs to me’ and all that. Dumb. 

And alphas were pretty dumb on top of that, with all that aggression and puffed up ‘I’m at the top of primary’ crap. Not Yuu’s style at all, which was to say it was *literally* his style. He was always the loudest guy in the room, the most aggressive, the one who commanded attention, dug himself in deep and refused to back down. He had  _teeth_ , according to his mother, was an omega with bite all his own and so wasn’t in need of anyone else’s. He had, by the end of junior high, figured everything out. 

His interest mostly veered towards beta and omegas, the sweet bubbly giggly kind who floated on air and always smelled like sun and sugar. Pretty ones, with easy smiles and legs for days. He knew what he liked and knew it well. 

And then high school and Asahi happened, as if the universe had looked down on him, laughed, and said ‘Hey, check this out idiot. You haven’t seen anything yet.’

It was almost scary, grossly disgustingly scary, how fast he’d gone from ‘I am the only one who will be doing any biting here’ to ‘please please I have never wanted anything like I want your teeth in my neck, take me, hurt me, keep me.’ He didn’t want to say it was instant but it might as well have been. Which wasn’t to say there wasn’t more to it that laying eyes on Asahi and everything that made him an omega short circuiting on the spot because Yuu liked to think if it was just the sudden emergence of ‘oh hey, I like height and broad shoulders and self-description smiles’ he could have kept that under control and snuffed it out. 

But there were feelings there too, that had sprung up in the wake of that instant attraction. There was easy companionship, shy smiles and quiet words, bumped shoulders and laughter. There was trust and dedication and anger and hurt and a bunch of other stuff that Yuu felt most intensely when Asahi was involved. It was a lot of things, too big and too much to sum up in words, that had brought them to this point. 

This point being locked at the lips in the storage room, mere days from the Yuu’s graduation, after a practice Asahi had helped out with (the new first years loved him), hands sliding and clothes askew. This was not the first time they’d kissed, or even the first time they’d done so in here (Asahi’s last year had been full of frantic make outs and rutting against each other back behind the rolled up nets) but this was different, because it had come on the heels of Yuu asking Asahi to bite him. 

Claiming has two tiers. Permanent claiming, with all the ‘forever linked’ that it implied, marked by scarring at the mating gland, and temporary claiming, with it’s more careful bites and bruising that needed to be redone often. Yuu was asking for the latter, because he knew Asahi wasn’t going to go for the former (they were too young, things were still in flux, who knew where they were going next.) and even in that he was pushing things. 

Not because Asahi didn’t want to. Yuu could smell how much he wanted to, had seen it in the way his eyes darkened and his pupils stretched when Yuu had moaned the request against his lips. “Bite me,” He’d all but panted and Asahi had shuddered, the hands (Big, amazing, strong, rough hands) on Yuu’s hips tightening then kissed his harder, deeper, held him closer. 

“We shouldn’t.” Was murmured against his lips, licked into his mouth regretfully like only Asahi could. “Not here, like this. Should be…nicer. I should…something better.” 

Yuu huffed, hips rolling down against the bulge he could feel under his ass. Asahi’s eyes crossed and his mouth dropped open. Yuu leaned close, until they were chest to chest, and pressed his mouth to the warm, pulsing skin of Asahi’s throat. He parts his lips, breathes hot and wet against *his* alpha’s skin, drags his tongue up to taste salt. Another push of his hips and a hard grind down.

“Bite me Asahi.” 

Asahi could get too caught up in being ‘Asahi first and an alpha second’. Whcih was nice. It was cute. Yuu loved that Asahi wasn’t some swaggering asshole who thought with his knot and thought he was owed things he’d never earned. He loved that Asahi worked harder than anyone else, was humble and sweet and always so awkwardly aware of himself and his strength. He was painfully careful with Yuu, kept a tight leash on all of the instincts that had to be buried in him somewhere. 

He didn’t scent mark without permission, and sometimes had to be bullied into even after being given the okay. He’d never pushed Yuu to spend a heat or rut together, had never even brought it up. He didn’t bite or growl or show his teeth when he was angry He didn’t puff up or strut or show off, didn’t demand or take. He didn’t even knot Yuu unless they’d agreed before hand and an amount of prep that gave new meaning to the term happened first. That was just how Asahi was. Yuu, for the most part, didn’t want him to be anything but the timid, stupidly sweet alpha he was. 

Asahi wanted to claim him nicely, take him out, treat him good, make it soft and slow and as painless as possible. 

Yuu wanted…something else. That part of him that was all omega, with sharp teeth and hard edges and demands, wanted to be claimed, yes, but more than that it wanted it to be demanded. Taken from him. He wanted it to be rough and primal and to feel the ache for days after. 

The issue of course was getting Asahi on board. Yuu didn’t want to force things, he wasn’t that guy, but he wasn’t above stacking the deck in his favor. Which was why he’d chosen tonight, when he could feel the first stirrings of his oncoming heat, had waited until after practice when he’d be sweat soaked and his scent would be at it’s strongest. That’s why he’d been showing his neck all day, tilting his head this way and that, lifting his chink when he stretched, rubbing at tension that wasn’t there when Asahi’s eyes trailed to him. That was why he’d dragged Asahi into this corner as soon as everyone else was gone and pushed him down to climb into his lap in spite of flailing and mutters of ‘I’m not even a student here anymore’. 

That was why he was doing this, rolling his hips slow, letting Asahi’s clothed cock ride along the crack of his ass, using his teeth to leave marks that would be faded by morning, sliding his hands under the alpha’s damp t-shirt to rake his nails over the hard planes of his abs. That’s why he wasn’t trying to hold back, letting all of his want and arousal roll out of him in thick, sticky sweet waves. 

That’s why he whined out a breathy “Alpha, please.” before bringing their mouths together again. Asahi’s lips were warm and soft, wet, slack in shock for a moment and then he was kissing back, harder, demanding more. Asahi’s tongue drags over the roof of his mouth, flicks against the back of Yuu’s teeth, glides against his own. He nips at his lips, sucks and tugs and Yuu lets him, parts his lips and happily lets Asahi take what he wants. 

(He makes a silent note to never speak badly about the ‘drive your alpha wild’ articles in supermarket magazines ever again. Who would have thought two little words-)

One of Asahi’s hands clamped onto the back of his neck; Yuu jerked, the feel of thick fingers pressing against his nape sending a jolt of tingling electricity down his spine and stealing the breath from his lings. The kiss ended with a wet pop, spit stretching and snapping between them when Asahi forced his head back, a low rumbling noise falling from his lips. for just a moment, Yuu could see a flash of alpha teeth behind Asahi’s lips. But they were gone quickly, Asahi’s hand slapped over his mouth, eyes wide and mortified. 

“Don’t be so nice.” Yuu’s heart fluttered in his chest as brown eyes swept over his face searchingly and the hand lowered slowly. He stared back, eyes sliding to half mast, and breathed out: “I want everyone to know I belong to you. I do, don’t I?” 

Asahi’s hand spasmed on the back of his neck and his eyes rolled back a little and then. Then the world shifted, flipped and Yuu was on the floor, on his stomach. It happened fast, he didn’t even register it until he was face down on the mats they’d been sitting on and those hands were on his hips, dragging his hips up. Asahi’s breathing had changed, deepened, and was coming in faster bursts. 

His scent was different too, had spiked hard and taken on a smokey, musky note. Yuu’s toes curled in his shoes; the smell made his mouth water. 

His shorts were yanked down and Asahi’s fingers pressed against him. Usually this was where he’d touch and tease for a while, slowly rubbing at Yuu’s rim until he was relaxed then working in one finger after another, not stopping until Yuu was a puddle of slick and need and stretched enough to take him easily.

This time there was a touch, fingertips gliding through the slick that had already leaked from him and pressure and-

Yuu shouted, back arching as two long, thick fingers pushed into him to the hilt. The fingers twisted and dragged back and he had to turn his head and bite down on his arm to keep from shouting again. It’s not painful, Yuu is wet and hard and that always makes him a little looser, but the stretch it…it tingles. Burns, a little, as Ashai’s fingers spread apart and pump into him; he pushed back into it, rides those fingers with a desperation he hadn’t realized was simmering in his stomach until that moment, and keens through teeth dug deep into his own skin. 

He bucked back when a third finger pushes in soon after, sparks flowing down his spine and thighs quaking, squirmed when finger tips press just right and then stay there, drifting in tight circles. He didn’t let up and maybe Yuu was drooling a little bit (a lot), soaking the fabric of his t-shirt, and his gums were itching and he couldn’t stop squirming. His backs arced up and his head and shoulders fell forward, face pressing into the mat. 

Slick was running down his thighs in thick streams and his cock was so hard, heavy between his legs. He was mumbling, Asahi’s name peppered with pleas for me and it was going to be embarrassing later, in hindsight, to realize he was fucking back onto that alpha’s fingers and drooling all over himself like it was the first time. 

He was going to blame being on the edge of his head, the heightened sensitivity, the need to be filled and fucked, the desperation. Anything else was just too mortifying, especially the way he near sobbed when Asahi’s hand pushed against the back of his neck again, a heavy weight forcing him more firmly against the mat. There was a shift in the world with that touch, a giving up and accepting of control, it was them falling into the most simple and basic thing in the world: alpha and omega. 

It was what Yuu wanted and yet he was shaking, mewling like he would normally *never* allow himself to, hips pushing back to chase after Asahi’s hand when his fingers slipped free. 

“Yuu.” Asahi’s voice was dark, thick. “Stop squirming around so I can claim you.”

He stopped. Went slack as Asahi curled over his body, the hand on his neck still firmly in place, pressed into him. It was not the easy slide he was used to; it was spreading and stretching wide with each thrust down to the knot, so tight Yuu couldn’t breath. Asahi settled down on him with enough of his weight to force him flat, to pin him down and make him *take* it. 

His cock rubbed against the plastic surface of the man beneath them, an uncomfortable sticky feeling that he couldn’t help but try to buck against in search of more. 

It was amazing. 

He didn’t want to say the world moved or anything like that, because lame, but. 

It might have. 

He was shaking, moaning and clawing at the mat, lost in the weight of Asahi’s body pushing down on him and the force he was being fucked with. It was bone rattling, teeth shaking, deep and hard and filthy. The slap of skin on skin and the wet sucking squelches as their body came together blended with the soft growling huffs from Asahi, formed a soundtrack he felt down in the marrow of his bones. 

When the hand on his neck finally let up it was to grab his him, smooth other the curve then hold tight. Asahi’s other hand touched his face, pressed against his lips and Yuu didn’t even hesitate in opening his mouth and sucking two in. He could taste himself, salt and bitterness, and moved his tongue around and between the digits without thought to chase the taste. He drooled around them, sucking and moaning. 

He might have, maybe, loved Asahi’s hands, those strong fingers and wide palms, before he’d loved the rest of him. He’d noticed them first, at least. Liked the feel of them in his mouth, pressing down on his tongue as they slid, messy and wet, past his lips. 

His brain whited out, every single thought dropping away under static. There was just this, just Asahi, just being open and filled and melting from the inside out. Just being held down, held open

Until it changed. A shift and he was being dragged up, legs forced to spread over Asahi’s thighs, made to lean back against his chest, dragged down as the alpha fucked up into him, tugged him down right over his swollen knot, tying them together with a wet squish. The world dimmed and, if not for the fingers pressing against the back of his throat, Yuu would have screamed his finish at the ceiling. Instead he whimpered it, cock spurting hot and thick over his stomach. 

Asahi’s hips roll, little grinding motions that rubbed his knot against fluttering muscles. It was a sharp, aching pleasure that came with it, made Yuu quake and thrash through the alpha’s finish, keen sharply around the fingers in his mouth. 

He’s almost forgotten about the bite, didn’t notice Asahi contorting and folding down until his mouth was there, teeth clamping down just behind his mating gland. His eyes rolled back and his body went limp, all the tension draining away like a plug had been pulled inside of him. 

He felt…warm. 

Good. 


	2. How Does That Feel

**Summary for the Chapter:**

> Another Asanoya omegaverse fill, so this seems like a good place to put it. Short, dirty, maybe sweet?

Asahi was covering him completely, torso pressed against his back, hips flush against his ass, pressing him down flat against the mattress. It was just enough to make breathing a little hard, every inhale and exhale something he could feel as his lungs strained, just a little, to expand and fill, enough to feel small and vulnerable, to know he had no control here. 

Not enough to hurt, because Asahi would never, no matter what game they might have been playing. 

He moved, a slow glide and nudge further in, grinding his knot into him, against the spot that made Yuu’s eyes roll back and fireworks go off in his head. He was in so deep, had all of his weight and power behind it, was filling him completely. Yuu felt him, hot and twitching up in his stomach, forcing all the air and sound out of him, claiming-carving out- a space inside of him like nothing else could. Another slow rock, pulling out just enough that he had to work his knot back in, force Yuu’s body to open and accept him over and over. 

It was all unhurried, shallow thrusts and, when their bodies met again, Asahi’s hips moving, pressing, dragging into figure eights. It was Yuu’s heart stuttering and his breath sticking as his nails dug into the mattress. Slow, but not lazy or easy; Asahi was panting above him and his chest was slippery with sweat where it pressed against Yuu. He groaned and swore, quiet and gentle and it sounded off from him even now. 

Asahi pushed in again, reached a hand down to spread him a little more so he could get, somehow, even closer, even deeper. Yuu felt him in his stomach, would have sworn to it if asked to, felt his body stretched so wide it burned but in a heady, addicting way that he wanted more and more of. 

“How does it feel?” Came from above him, close but far way, coming through a tunnel, muffled, at the same time. “Yuu?” 

Yuu was quiet, too far out of his head, floating somewhere else, and drowning in everything that was Asahi to form any words. 

Another push and Yuu’s toes curled and his cock, trapped between himself and the slippery sheets that provided not nearly enough stimulation, spilled in sticky pulses. Asahi stopped moving, stayed buried in so deep Yuu couldn’t breath around him, and bent himself enough to mouth at the shell of his ear and croon sweetly as he trembled and thrashed under him. 


	3. Chapter 3

**Summary for the Chapter:**

> Prompts were Kneel/Regency AU

“Asahi,” Suga called, poking his head into the kitchen. “Lord Nishinoya is asking for you to help him with his hair in the bath.” 

Asahi set down down the potato he was peeling and handed his knife over to Yamaguchi to take over, hoping that he’d managed to keep his face free of emotion this time. At first he’d been prone to blushing bright red and being unable to look anyone in the eye before or for hours after. Now he could at least keep is head high as he brushed past Suga in the doorway. 

He didn’t even flinch when the other’s hand darted out to grab his arm, even though his heart jumped then started hammering in his chest. “Asahi you...” Suga stopped, sighed, and shook his head before letting go and waving him off. Asahi was quick to move on, hopeful that would be the end of things and he wouldn’t have to get an embarrassing lecture on being careful, remembering his place, and that high society alphas couldn’t be trusted and shouldn’t be cared for like Daichi well-meaningly kept giving him.

“At least don’t let him spill in you!” Suga called.

“What?” Yamaguchi squawked. 

Asahi ducked his head and walked faster. 

\---

Yuu was in the tub, cast iron and high backed, when Asahi slipped into the room. His head was tipped back over the edge, his eyes were closed, his arms draped over the sides, and his soaking wet hair dripping to make little puddles on the floor. Steam was rising from the surface, filling the room with thick, cloying heat the seemed to soak right through the thin fabric of his gown, making it stick to his skin. 

An eye cracked open lazily. “Asahi. Come here. Kneel.” He pointed to a spot next to the tub, tone light enough to make the order not really an order. Asahi complied, frowning a little as water soaked through his dress at the knees. 

Yuu reached for him, first pulling the pins that kept his hair up out, then running a hand through it as it fall down around his shoulders. He sat up, water sloshing up the sides of the tub, and moved closer to the edge, leaned over and pulled Asahi in to kiss him warmly. The wet slide of their lips was a familiar thing, gotten just right with time and practice. A touch of tongue at the seam of his lips and he opened up for the alpha, touched their tongues together, tasted sugar and fruit in Yuu’s mouth. 

A flick up, a rasp of teeth against his bottom lip before it was pulled into Yuu’s mouth, sucked and licked slowly, sweetly as he hauled in closer. Asahi’s hand slipped from the rim of the tub into, hot water soaking into stiff fabric past his elbow and splashing up around them. 

Yuu drew back with a wild laugh and, when Asahi frowned, kissed him again, quickly. “Sorry, Asahi. How about you get in with me?” 

Asahi stood to get rid of his clothes but a tug at his hand had him stumbling forward and bumping against the edge of the tub. He blinked and Yuu smiled, toothy and hungry. 

“Like this.” 

He made a face, tried to look unimpressed but, all the same, he slipped off his slippers, stockings, and everything else into he was in just his simple shift then stepped into the water. He lowered himself over Yuu and settled in his lap, knees sliding over the slick bottom to bump against the back, hands gripping the edges. He peered down at the smaller man, tried not to smile as familiar hands slipped under the soaked through fabric of his clothes, pushed them away from his skin to lazily float in the water, and curled around his thighs to drag up to his ass. His cock was hard, rubbing against Asahi’s balls and riding along the sensitive skin behind them. He squirmed a little, tried to settle just right to grind down against him, smiling at the breathy moan that rose up from the alpha and bounced off the walls around them. 

Yuu’s hands cupped his backside, squeezed and tugged, encouraging and guiding him. Lips drug along his chest, parted to nip and lick at skin going red from the heat, before closing around his nipple. Asahi licked his lips and gripped the tub harder, a jolt of sensation cutting through him at the rough rasp of tongue and scrap of teeth. Yuu’s hands kneaded his ass as the alpha rocked up against him, spread him for rough fingers to drag along the cleft seek out

He jolted up, a surprised yelp falling from his lips; he’d been expecting it but there was always that moment of surprise, disbelief, before he was melting into Yuu. 

“Hi.” Yuu said, impish and teasing as he craned his neck up, fingers pressing up into where Asahi was already slick, just from the kiss and the anticipation on the walk up here. “Will Suga mind if I keep you for a little while.” 

His mother would have called him easy. Asahi supposed it wasn’t...untrue. 

“Hello.” Asahi returned, bending down to close the gap. “I think it will be okay.”  

The thing was Asahi wasn’t like Yamaguchi, who was will finishing up at the Karasuno Omega School and had his eyes on university, or Koushi who had taken this job to use the Nishinoya connects to get himself into medical college, the only omega in the place. He didn’t have a Tsukishima, who was a minor enough member of the gentry and the second son so no one cared that he was engaged to a commoner, or a Daichi who worked hard as the head of the stables and was pooling his money with Suga’s to put him through school. 

He was just another Azumane working for the Nishinoyas, as they had for the past five generations, content with his place in the household of a minor noble. All he had were his friends, who he loved, and his family who would be scandalized if they knew what he was up to, and a lover he couldn’t keep. It was all his choice, his employers were notoriously generous and kind as well as liberal when it came to omegas, and so if he wanted to go to school they would back him. 

He’d had a few interested suitors but he’d turned them aside, never feeling that perfect rush, that stirring in his stomach, that moment of strength and perfect clarity that he felt with Lord Nishinoya. He wasn’t so foolish as to imagine a future for himself here, a proper one, but he wasn’t yet ready to settle for the sake of security either. 

So he kept doing this, first at the main estate and then here, at the home Lord Nishinoya had moved to in the city for the sake of school that Asahi had followed to at his lord’s request. They pretended it wasn’t happening, and the rest of the household pretended around them but it was like living with his breath held, waiting for the moment where it all fell apart around him. Eventually his lord would need to marry, and marry well, or he would get bored of Asahi (the man was notorious for his roaming eye, brash personality, and shamelessness. Asahi didn’t imagine he was the first person, or servant, to get caught up like this but, then, maybe he was. It wasn’t for him to know) or they would be caught and Asahi sent elsewhere to avoid a scandal. 

But for now this was what he had.

Yuu’s fingers slipped free of him. Asahi lifted up, felt Yuu’s hands slip under him, between their bodies, then lowered himself again, bottom lip trapped between his teeth to hold back his sigh as their bodies came together. He swiveled his hips, sliding up slow, and dropped back. It didn’t take long to find the right rhythm, slow drags and filthy grinds as he rode out firm, determined way Yuu fucked up into his body. 

“Stay the night?” Yuu panted, fingers fluttering over his skin, eyes wide and dark, lips kiss swollen and spit slick. As if Asahi could say no when he looked up at him like that.  

Asahi nodded, lips quirking into a breathless smile when Yuu beamed up at him.


End file.
